The present invention relates to ladder guards for the purpose of preventing people, particularly children from climbing a ladder. The invention is particularly directed to ladder guards for extension ladders. The invention also relates to security devices for deterring theft of ladders.
Ladder guards for preventing or deterring people from climbing ladders are well known in the art. U.S. Pat. Nos. 3,225,863 to Ludlow, 4,181,195 to Clarke, 4,450,937 to Broughton and 4,579,197 to Spurling are representative. The prior art guards typically comprise a flat, planner member that is secured to the ladder, covering the rungs of the ladder to prevent its use. However, these guards are not fully satisfactory, especially as applied to extension ladders.
Commercially available extension ladders have parallel, spaced apart side rails with a plurality of rungs extending between the side rails. The side rails have a depth that is greater than the depth or diameter of the rungs. Accordingly, conventional ladder guards that are flat and planar will engage the ladder side rails, leaving a space in between the back of the guard and the rungs. A guard of this type will hinder a person from climbing the front of the ladder. But, a person, especially a child, may nevertheless climb the ladder from the back or underside. Many conventional ladder guards, e.g., as in the Ludlow '863 patent, do not address this problem.
Applicant is unaware of any prior art ladder guards specifically applicable to conventional extension ladders. The above cited prior art ladder guards could not be successfully applied to commercial extension ladders for several reasons. One, the prior art guards are typically designed to fit only one ladder. They may not fit ladders of different sizes. In addition, the cited prior art ladder guards are all for single section ladders. These prior art ladder guards may be unsuitable for extension ladders that have multiple sections. Specifically, if the ladder guard is longer than the length of the unobstructed lower section, it may not be possible to install the ladder guard to the lower ladder section. The cited prior art does not attempt to solve problems incident to providing a guard for extension ladders.
Another problem in the art is the theft of ladders. Painting, siding, and general contractors often need to set up ladders with scaffolding therebetween. If the job extends for a period of several days or more, the contractor may leave the ladders and scaffolding in place to avoid the time and expense of disassembling, storing and locking the ladders. Due in part to the substantial value of quality ladders, theft has become a problem. Thieves may visit a job site during off work hours or at other times when the contractor and his crew are absent, disassemble the scaffolding, retract the ladders and abscond with the same.
For the foregoing reasons, there is need in the art for a ladder guard that prevents people, especially children, from climbing the ladder from the front or back, that is particularly suited for use on commercially available extension ladders, and that functions to deter theft of the ladder.